Index: trunk/SDToolBox/extract_waves.py
===================================================================
diff -u -r35 -r36
--- trunk/SDToolBox/extract_waves.py	(.../extract_waves.py)	(revision 35)
+++ trunk/SDToolBox/extract_waves.py	(.../extract_waves.py)	(revision 36)
@@ -78,11 +78,7 @@
             self.check_for_longitude(lon)
             for lon in self.__input_lon]
         years = self.generate_years_array(year_from, year_to)
-
-        nn_lon_idx, nn_lat_idx = self.__get_corrected_lon_lat(
-            directory_path, cases_dict
-        )
-
+        nn_idx = None
         for n_variable, variable_name in enumerate(variable_dict):
             case_name_value = variable_dict[variable_name]
             for year in years:
@@ -99,6 +95,11 @@
                         'does not exist or could not be found.')
                     continue
 
+                if not nn_idx:
+                    nn_idx = self.__get_corrected_lon_lat(
+                        case_file_path, cases_dict
+                    )
+
                 # Lazy loading of the dataset.
                 with Dataset(case_file_path, 'r', self.__ds_format) \
                         as case_dataset:
@@ -107,7 +108,7 @@
                             cases_dict[self.__out_val_key][variable_name],
                             case_dataset,
                             variable_name,
-                            (nn_lon_idx, nn_lat_idx)
+                            nn_idx
                         )
                     # Get the time for the variable.
                     if n_variable == 0:
@@ -157,11 +158,11 @@
                 axis=0)
 
     def __get_corrected_lon_lat(
-            self, directory_path: str, cases_dict: dict):
+            self, ref_file_path: str, cases_dict: dict):
         """Gets the corrected index and value for the given input coordinates.
 
         Arguments:
-            directory_path {str} -- Parent directory.
+            ref_file_path {str} -- Path to the refernce file.
             cases_dict {dict} -- Dictionary with all values that need format.
 
         Returns:
@@ -170,7 +171,7 @@
         nn_lon_idx = []
         nn_lat_idx = []
 
-        ref_file_path = self.find_default_file(directory_path)
+        # ref_file_path = self.find_default_file(directory_path)
         # Hardcoded:
         # base_file_name = 'Hs\\era5_Global_Hs_1981.nc'
         # ref_file_path = os.path.join(directory_path, base_file_name)